1. Field of the Invention
The present invention generally relates to geometrical instruments for measuring distance. More particularly, this invention relates to an improved retractable, tape measure.
2. Description of the Related Art
Retractable tape measures have been popular for many years and have often been the subject of patent grants. For example, see U.S. Pat. Nos. 3,908,277, 4,153,996, 4,194,703, 4,439,927, 4,748,746, 4,938,430, 5,210,956 and 5,983,514.
In general, a retractable tape measure includes some widely recognized features, including: a metal tape that is retractably mounted within a housing, a retraction means for retracting the tape through a housing opening, an end stop for preventing the free end of the tape from retracting into the housing, and a lock which releasably secures the tape in an extended position. In order to provide stiffness to such a tape so that it's free end can extended to a maximum distance from its housing without bending, the tape is usually manufactured with lateral cross-section curvature created by having the tape's ends turned upward. This curvature also serves to differentiate the top side of the tape.
All of the above referenced tapes also share some other, not so widely recognized, features which serve to significantly limit their usefulness. These features include all these tapes having: (1) retractable tapes that extend from their housings at a point on the side of the front side of the housings which is proximate the housing's bottom surfaces, and (2) measurement indicia on only the top surface of the tape.
The reason for these features is apparently that such tapes are primarily intended for use in making measurements on surfaces or in planes that are lower than the eye level of the user, and where there are no obstructions above the plane of a desired measurement which would necessitate a user having to bend the tape downward so as to reposition the top portion of a tape's housing out of the way of such an obstruction. The logic of this last statement becomes apparent when it is recognized that the turned upward edges of the tape destroys its vertical symmetry, and means that such a tape cannot just be turned over, so as to make the tape's top surface indicia visible or to reposition the top portion of the housing out of the way of an obstruction, without losing the stiffening and avoidance-to-bending characteristics provided by the tape's turned upward edges.
Thus, despite their popularity, such standard tape measures are not always easy to use. For example, electricians and others often encounter significant problems in using a standard tape measure when they are making measurements from a wall to a distant spot that is more than an arms length away on an adjoining ceiling. See FIGS. 1-2. The first obstacle encountered is the lack of any markings on the tape's bottom side. Meanwhile, the numbers on the tape's top side cannot be seen by its user while he/she is holding the tape up against the ceiling. Unfortunately, as noted above, the tape cannot be turned over or the top portion of the tape's housing moved away from the ceiling without losing the stiffening effect of the tape's turned-up edges.
U.S. Pat. No. 1,986,551 discloses a steel, retractable tape which has indicia on the tape's bottom surface and at least some degree of lateral cross-section curvature. However, this tape measure differs from most of the others in that it has some unique, essential elements. For example, the end stop of this tape measure is rotatable to allow for the making “inside and outside” measurements. Similarly, the opening for this tape measure is unusual in that it can be interpreted as having a continuous boundary edge that extends from 34,′ where the edge of the housing forms a line at which “inside” measurements are taken, and follows the inside edges of the guide shoes 14 and 15 so as to ensure that “all of the graduations and all of the numbers (on the tape) are fully exposed and easily readable.”
Thus, despite this prior art, one finds that standard, tape measures are not very user friendly. The need exists for an improved, retractable tape measure that is easier to use.
3. Objects and Advantages
There has been summarized above, rather broadly, the prior art that is related to the present invention in order that the context of the present invention may be better understood and appreciated. In this regard, it is instructive to also consider the objects and advantages of the present invention.
An object of the present invention is to provide an improved, retractable tape measure that will overcome user problems such as the one described above.
Another object of the present invention is to provide an improved, retractable tape measure that can be used, for measuring extended distances, just as easily when those distances are on a ceiling or a floor.
Other objects and advantages of the present invention will become readily apparent as the invention is better understood by reference to the accompanying drawings and the detailed description that follows.